Hydraulic drill press



Apk-m5, 1947. J, w. KARWEIT M1894@ HYDRAULIC DRILL PRESSA Filed Nov. :5,1942' 4 sheets-sheet 2 pril l5, 1947.

J. w. KARWEIT 2,418,840

HYDRAULIC DRILL PRESS 4 Sheets-Sheet 3 Filed Nov. 5, 1942 IN V EN TOR.Wezf ///.5` Arrafwfr Patented Apr. 15, 1947 @NME HYDRAULEC DRILL PRESSApplication November' 3, 1942, Serial No. 464,340

(Cl. iT-32) 9 Claims.

The invention relates to power driven tools and more particularly todrill presses and certain improvements therein adaptable also for usewith similar tools.

Aside from questions of expense, it has long been the practice withdrill presses or the like to provide a feed arrangement for advancingthe drill with which the operator could feel the feed. As a generalrule, with this arrangement, the

operators were so trained that whenever the feed began to feel heavy tothem, they would bac-l: the drill clear of the work to remove the chipswhich filled the drill flutes before feeding the drill further.

In some instances, where a drill press was set up to work with oneparticular metal, and no other metal was to be used, it was possible todispense with the arrangement for feelingthe feed. In fact, one machinedrilling only one metal all the time could be automatic. However, wherethe drill press would be used for a miscellany of work materials, it wasnecessary that the feel of the drill be provided since, underconventional practices, stringy metals such as copper, aluminum andnaval brass would be encountered. Without the feel of the feed, drillbreakage would be very high.

Furthermore, even where the feel of the feed is present in a hand-feeddrill press or the like, the tool breakage is high, particularly wherethe press is operated by inexperienced operators, or where a deep cut isto be made and the operator seeks to establish a favorable productionrecord.

In other instances, as Where a Work piece, such Vas a carburetor body,is nearing completion great care must be exercised to safeguard againstbreakage of tools in the Work piece that would scrap the piece. In someinstances the final cuts are made by hand.

Much time is consumed in performing the operations conventionally, andthe danger of drill breakage with deep cuts is always imminent.

In the present invention not only is'the prime cause of tool breakageeliminated, namely, the binding of the chips in the drill iiutes, asmore particularly discussed in my co-pending application Serial No.455,417, reference to which is hereby made for other and furtherdiscussion upon this point, but the present invention also provides animproved drill press or the like, in which the feel of the feed is notessential to the handling of different metals.

Another object of the invention is to provide an improved drill presswhich is less tiring upon the operator mentally and physically tooperate,

and can be operated successfully by unskilled as well as skilledoperators.

A further object is to provide an improved handfeed drill press whichcan be operated manually for special Work or semi-automatic forproduction Work.

One of the objects of the present invention is to provide thecombination of a rotary drill and a hand forward feed in which the feedtraverse effort is a substantially constant factor.

Another object of the invention is to provide an improved drill presswhich amateurs may use, who are unskilled mechanically, with little fearof drill breakage during deep cuts of a stringy metal or metals and inwhich the feed traverse effort can be adjusted and maintained constant.

A further object of the invention is to provide a drill press or thelike whose feed traverse characteristics may be varied manually orautomatically.

A further object of the invention is to provide a feed arrangement for adrill press Where the rate of feed can be kept uniform automatically atany one of a plurality of feed rates, depending upon the size of outbeing made.

Another object is to provide a drilling process for stringy metals orthe like in which a single feed traverse is limited only by the lengthof the flutes upon the drill.

Another object of the invention is to provide a device of the classdescribed which is simple in construction and operation, and inexpensiveto manufacture and maintain.

being among the objects of the invention, other further objects Willbecome apparent from the drawings, the description relating thereto andthe appended claims.

Referring now to the drawings:

Fig. l is a side elevation of a drill press illustrating one of theembodiments of the invention;

Fig. 2is an enlarged vertical section of the per portion of the drillhead shown in Fig. 1;

3 ,an enlarged vertical section of the portion the drill head shown inFig. 1;

i is a section taken upon the line li--fi in lewe ri enlarged sideelevation of the rapid feed traverse control;

is a Laction taken upon thel line 6-5 in isa-n Fig. 'l is a crosssection of the spindle indicatlustrating a preferred embodiment ofcertain features of the invention; and Y Fig. 9 is a diagrammatical Viewof the hydraulic system employed in the invention.

In the practice of my invention, I prefer to provide a constructionwherein a hydraulic medium is employed to control the feedcharacteristics during a drilling operation. This feed characteristic ispreferably one in which a drill is fed a short distance each revolutionand permitted to dwell at the end of its feed position over theremaining portion of its revolution. Thus, Ythe chip which was formedduring the feed movement and part of a rotation is broken away dur ingthe remainder of said rotation to asize which will clear the flutereadily without any binding or scoring of the walls.

Referring now to the drawings in further detail, the drill press headSi] is slidably mounted in locked relation upon a standard il by meansof a split sleeve :ar-rangement `lf2 so that a drill chuck i3 may besuitably located :with `respect to a work -piece le disposed `upon theworlrrtable l5. Standard Vi l, in turn, is supported upon -a base l5secured to a floor or table l1 by bolts Ilill.

As viewed in Fig. l, a motor is mounted to the left `of `the standard ilupon a base member 2l which is pivoted as at `.22 to an adjustablecarrier 23. The drive shaft '2-4 of 'the motor is preferably disposedvertically and-carries a `pulley vthat receives and drives a '-v' belt23. The carrier 23 is provided with rod-supports '2l' slidably receivedin collars I2li .by which the tension upon the V 'belt 2e may beadjusted, and the pivot 22 permits the motor to be pivoted about aShorizonta'l axis to release the Ybelt in event the belt is to beshifted to any other groove upon lthe pulley 2E than that shown.

The shaft 24 of the motor extends beyond the motor housing at both endsand at its lower end receives a. drive coupling 36 .by which .the driveshaft `of `a hydraulic pump 132 is driven. The pump 32 'is mounted bybrackets 33 `and bolts 34 to the `lower part of the pump casing andcomprises a pump compartment L35, a sump 316 and a pressure .reliefvalve -3'1 by which 'the hydraulic duid present in the pressnreline .38is maintained at .a constant pressure, the pressure relief valve 3lbeing adjustably set to relieve the line 38 to the sump Yabove the .uidsupply and pressure needed to feed any particular drill into the workpiece i4. Upon the right hand side of the sup port H the head lll -is`provided with `a cored enlargement lo machined to receive the workingparts that will now be described.

Within the cored enlargement 43 a hollow shaft 4l is journalled whichcarries at the lower end thereof a sleeve '42, the inner surface 43 ofwhich'constitutes a pressure cylinder. The journalling'of the'shaft diis accomplished by means of a pair of preloaded frictionless bearings'44 held in place in a suitable bearing cavity 45 against a shoulder 43by a jam nut 47 threaded into the outer end vof the cavity. Preloadingof the bearings is accomplished by the spacer t8 between the inner racesbeing slightly wider than the spacer 5B between the outer races. The jamnut l1 and shoulder 46 cooperate to tighten the outer races against theouter sleeve to load the bearing members.

The lower end of the shaft si has an enlargement 5l thereon receivedwithin the upper end of the sleeve 42. The upper rim of the sleeve 42 isupset as at 52 around the inner shoulder of the head El where it isbraze'd as at 53 Vto the reduced portion of the shaft 4l beyond the head5| to provide a shoulder against which rests the inner race of the lowerone of the two bearings 44.

With this arrangement upward thrusts exerted by the sleeve 152 are borneby the jam nut 4l while downward thrusts of the sleeve 42 are borne by aset screw collar 5A locked to the shaft 4l and resting against the innerrace of the upper one of the two bearings G44. A driven pulley 55 issecured to the shaft 4l above the collar 54 by means of :a Woodruff keyE6 and a set screw 5l.

At its lower end the sleeve 42 is journalled in the bearing cavity 58 bymeans of a frictionless bearing 33 held in place by a bearing retainer6l threaded into the lower end of the enlargement dil. The lower end ofthe member 42 is flanged outwardly as at 62 and tapped longitudinally asat 63 to receive the ends ofthe bolts 64. The included shoulder 65 of.the flange rests against the inner race 66 of the bearing 60 and a seal61 is disposed between the enlargement 40 and the sleeve 42 as held inplace by a gland washer 68 assembled ahead of the outer race of thebearing 60.

A driven shaft 'i3 having a splined outer face, as'sectionally shown inFig. '7, is received inthe cylinder 43 of the sleeve 42 where it issupported at the upper end by a piston head 1| having a seal 72 on thetop thereof held in place by a bolt i3. The rotary drive between the'sleeve 442 and the shaft lil is accomplished at the lower lend of theSleeve 42 by means of splined female runner 14 for the shaft 'lil lockedin place 'by the bolts 64 with alternate washers 'T5 and seals .76 heldin place around and in the splines of the shaft '10 where the shaft lllextends beyond the runner 14.

With this arrangement, whenever a hydraulic fluid under pressure issupplied to the cylinder d3 through a bore l1 provided for 'that purposelongitudinally through the shaft 41, the shaft 'fill is forceddownwardly to provide 4a "forward :or feed traverse for the chuck 'I3that is supported conventionally on the lower end of the shaft 'lll bymeans of a shank 18 received in a taper 18B,

Reverse or return traverse of the shaft 'lil is Vac complished byapplying hydraulic fluid pressure to the cylinder 43 below the head 1I'as -by a passageway 8l drilled through the enlargement 40 of the headil) to a recess 82 in the inner wall from whence the fluid reaches theinterior of the sleeve 42 through perforations 83 provided inthe sidewall thereof where they register with the groove 82.

With the description thus far, it will be understood how the drill chuckI3 and drill I'3a is rotated by the motor 2B through the belt 25 andraised and lowered bodily by means of alternately applying theAhydraulic fluid pressure developed by the pump 32 above and below thepiston l-I in the cylinder 43.

The control of the piston will now be descirbed:

Referring to Fig. 2, the upper end of the shaft 4l has secured thereto,as by 'threading `88, a rotary valve member 3B having a circumferentialgroove 9i therein and, as more particularly shown in Fig. 4, an arcuateport 92 in its upper face 93. The port 92 and the groove lll are -ncommunication with the vcylinder 133 through bores 94 opening into thebore 11. The rotary valve is received in a valve'housing 195, secured tothe'head i3 by means of an 'integral varm `93 held in place upon `anextension 9! of 'the 'enlargement@ by means of bolts 98.

The face 93 of the valve member 90 is held in contact with a face |inthe valve 'compartment 0| by means of a retainer |02 threaded into thelower opening as at |03 of the valve compartment. The retainer |02carries a packing seal |04 resting against the outer surface of theshaft 2| as held in place by a gland nut |05. The upper face of thevalve nut |02 supports one race of a irictionless bearing |06, the otherrace of which carries the rotary valve member 90.

Through the valve housing 05 a passageway |01 is drilled to open uponthe face 93 at a port |08 which registers with the port 92 in the rotarymember. The ow of hydraulic fluid through the passageway |01 iscontrolled by means of a needle valve I I0 as supplied with hydraulicuid under pressure from the line With this arrangement of the ports 92and |08, the supply of hydraulic iluid to the cylinder 43 isintermittent in quantities controlled by the needle valve H0. Morespecifically, each time the chuck and drill I3 revolve the ports 92 and|08 are in communication with each other throughout a portion of therotation, and out of communication with each other throughout theremaining portion of relative rotation. Hydraulic fluid is supplied tothe chamber 43 in quantities metered by the needle valve ||0 during thetime the ports 92 and |08 are in communication with each other, and thissupply is interrupted when the ports 02 and |00 are moved to relativepositions out of communication with each other. With this control, thedrill is alternatively fed into the work to cut some metal and then heldat the end of that feed to break the chip thus cut before being fedfurther through a series of successively identical steps timed inrelationship to the rotation of the drill in the work.

Hydraulic fluid under pressure may also be supplied t the cylinder 43above the head 1| through a groove 9| which is in continuousregistration with an opening 2 to receive fluid from the line H3. Inthis way, by selecting which of the two conduits or ||3 is to supplyhydraulic fluid to the cylinder d3, the piston may be alternativelysubjected to a metered intermittent flow or an uninterrupted flow. Thisselection is made by means of a valve I@ located in a valve housing ||5fastened to the head l0 as by a split collar H6 and a bolt It ispreferred that the valve Hd be controlled automatically and adiustablyin relationship to the position of the piston ll in the cylinder 43, thevalve being disposed to provide an uninterrupted ow to the cylinder d3to provide a rapid forward traverse until the feed traverse station isreached. at which time the intermittent metered supply of hydraulicliouid is substituted to provide the feed traverse and chip breakingaction just described.

This transition from the rapid forward traverse to the feed traverse isaccomplished by means of a dog |20 adiustably mounted upon a shaft |2|carried by the rotary shaft 'l0 by means of a collar |22 held in placeby a frictionless bearing |23. The dog |20 is mounted upon the shaft |2|for vertical adjustment by means of a slider |24 which can be clamped inplace by a winged nut |25.

For purposes of actuating the valve by vertical movement of the dog |20an L-shaped arm |21 is mounted upon the outer end of the valve H4 withone of the arms being engaged by and moved by the dog |20 when the dogmoves downwardly to the position shown in phantom |28, and the other ofthe arms being engaged by the dog |20 when the dog is moved from itsposition |28 to its full line position as shown in Fig. 5. As the dog|20 moves downwardly, it yields inwardly, supported by springs |30, tothe degree necessary to clear with close contact the arm |27. Pins |3|are provided to support the dog- Bit in sliding relationship withrespect to the follower 2li to provide for the yield described.

In the position of the valve shown in Fig. 2 the valve is the same asthat shown in Fig. 5 wherein the port |32 leading to the line M3 is incommunication through the valve passageway i3 with a iiuid supply line|33 and its port i3d. in this position the piston '5| is moveddownwardly by a constant and uninterrupted supply of hydraulic fluidunder pressure in the supply line |33 until such time as the dog |20contacts the arm i2? to move the valve to its alternative position inwhich the valve port |30, communieating with the line i, is placed incommunication with the passageway |35 and the port |34 through the Tpassage itl in the valve Hd. In this position the piston 'il issubjected to the intermittent metered feed provided when the cylinder'33 is connected to the line lil, as described.

The operator controls the supply of hydraulic iluid to the conduit |33by means of a two-position valve Mii. As more particularly shown in Fig.the pressure line 38 is placed in communication with the supply line |33through a slot iii cut in one side of the valve M0 where it willregister with the ports |42 and H13 for the lines 38 and |33respectively.

The leading baci# to the sump 3 is indicated at |555 and in the positionkof the valve shown in Fig. 3 the space in the cylinder i3 below thepiston 'ii is placed in communication with the sump line through theport led by means of a slot ii'i upon the other side of the valve whichestablishes communication between the lines 8| and M5.

After the rapid forward traverse has been accomplished and the feedtraverse allowed to proceed until the drill cuts to a suitable depth,the valve i420 is rotated counter-clockwise to the position shown inphantom his in which the port M2 of the pressure line 3S is placed incommunication with Jrhe cylinder below the piston through the line Si toforce the piston. upwardly and provide a rapid reverse traverse for thedrill, and the cylinder ifi above the piston 'H is drained back to thesump by the port M3 and the supply line |33 being placed incommunication with the port |65 leading to the sump line N5.

However, since upon the reverse stroke of the piston 'il the cylinder|53 above the piston is still in communication with the supply line |33through the needle valve l0, I provide a by-pass for the valve iid inthe form of a conduit |50 connected to the conduit Ht by means of a Tiitting |5|. The other end of the conduit |50 is adapted to be placed inopen communication with the sump line |45 through a bore |52 cooperatingfor that purpose with the valve slot i4 The position of the valve |620is determined selectively by the operator by means of a handle 53, theconstruction and the movement of the handle being so correlated thatforward traverse and feed movement of the drill is-established when thehandle is moved downward and the reverse traverse of the drill isaccomplished when the handle is moved upwardly. The valve |40 closes thebore |52 when the handle is in its down position, thereby permitting thevalve IM, to function in the manner described.

The valve lit and dog l2@ are further constructed and arranged so thatwhen it is desirable to feed the drill into the work without benefit ofthe metered intermittent supply of fluid, it can be done by the dog Idilbeing removed from a position actuating the valve l i4. Manipulation ofthe handle it is then relied upon to regulate or meter the fluid supplythrough the port ldd to the supply line 'iSB and the line H3. In thisway, the device not only can be used to drill with a chip breakingaction, but also can be used as any other standard drill.

On the other hand, by incorporating another dog l upon the shaft l2! toactuate the valve ll at the lowei` limit of the feed, the drill presscan be made to operate fully automatically after a forward traverse isinitiated. With this arrangement (not shown) the second dog |213 wouldmore the valve Mil from its forward traverse position, as shown in 3, toits alternate reverse position, shown in phantom M8, it being understoodthat suitable feed limit stops could be provided or arranged todetermine the depth to which the drill is fed into the work Hi.

Referring to Fig. 8, an embodiment of the rotary valve is shown in whichthe valve is disposed within the head enlargement 4D so that the belt 2ecan be removed and replaced readily. In this construction the rotaryvalve member 96a is secured to the shaft lla between the bearings fidawith the ports mila and ila opening upon the inner face of the combinedbearing cavity, and valve chamber 45a where they register with thecircumferential port 32@ and groove dia respectively. Otherwise, likenumbers refer to like parts throughout the several views.

Operation Presupposing that the motor 2D is rotating with the handledisposed in its upper position, a pressure is built up in the pressureline 38 to the degree determined by the relief valve 3i' and hydraulicpressure is applied to the cylinder 43 below the piston ll, where thedrill and drill chuck i3 are held at their upper or retracted limit.Then, when the handle 53 is moved to its downward position, pressure inthe line E38 is supplied in full measure to the cylinder i3 through thesupply line 133, line H3, valve conduit 35, and groove Si to provide a,rapid forward traverse for the drill 13a until the dog t28 contacts thearm l2? and moves the valve l it to its alternate position in which thefluid supplied by the supply line 33 is applied through the conduit llito the cylinder as metered by the needle valve iii) and interruptorValve 89. In event the drill 43a is of small diameter the metering valveIl@ is adjusted to a minimum flow, whereas if the drill in the chuck i3is of large diameter the valve il!) is adjusted to increase the flow,the valve being operated by a handle extending beyond the casing it@employed to shield the parts from damage.

After the piston li has been fed forward to carry the drill to theproper depth, the handle 53 is raised manually or automatically to itsupper position, at which time the cylinder i3 above the piston is placedin communication with the .sump through the conduit H3 and by-pass ldFluid under pressure is supplied below the piston l through the conduitSi to force the piston upwardly.

vThe reverse traverseV will be faster than the 8 rapid' forward traversesince the` displacement of the piston 7l: is greater for the same amountof fluid below the piston as compared with the same amount of fluidabove the piston, the piston in other words constituting a differentialarrangement.

Whenever the valve H4 is left in the position shown in Fig, 9 and Fig,2, as by removing the clog Id from a position actuating the arm |21, thefeed movement of the drill iscontrolled by the handle |53, same being asmooth forward feed and a smooth reverse traverse, the speed of which isregulated by the degree of communication permitted by the valve MDbetween the respective ports in relationship to the position of thehandle.

Having thus described the invention, the man ner in which the objectsare accomplished will be understood more clearly when it is noted thatwith the present invention, regardless of the metal being out by thedrill, all the chips come out a uniform size, a size that can bedetermined by the length of the arcuate ports 92 or 92a, and the degreeof feed permitted to exist by the adjustment of the valve HU, it beingpossible with this arrangement to provide chips small enough to readilyclear the flutes in the drill and be handled thereafter in much the samemanner that one would handle sand, as distinguished from long curls andstringy chips that would otherwise bind in the drill and cause drillbreakage.

Consequently, although certain embodiments of the invention have beenshown and described therein, it will be apparent to those-skilled intheart that other and various modications of the invention may be madewithout departing from the spirit of the invention, the scope of whichis commensurate with the appended claims,

l. A drill press having a head and a work table, a plurality of axiallyaligned shafts, means for moving said shafts longitudinally withArespect to each other including a cylinder upon one shaft and a pistoncarried by the other shaft disposed in the cylinder, means for rotatingthe shafts simultaneously, means for mounting a drill on one of theshafts, means for introducing fluid under pressure into said cylinderfor moving one shaft longitudinally with respect to. the other, andmeans driven by one of said shafts for intermittently interrupting thesupply of iiuid under pressure to, said cylinder.

2. A drill press having a head anda work table, a plurality of axiallyaligned shafts, means for moving said shafts longitudinally with respectto each other includng a cylinder upon one shaft and a piston carried bythe other shaft disposed in the cylinder, means for rotating the shaftssimultaneously, means for mounting a drill on one of the shafts, meansfor introducing fluid under pressure into said cylinder forlongitudinally moving one shaft with respect to the other, and meansdriven by one of said shafts for intermittently interrupting the supplyof fluid under pressure to said cylinder and including a iiow meteringvalve.

3. A drill press having a head and a work table, a plurality of axiallyaligned shafts, means for moving said shafts longitudinally with respectto each other includingv a cylinder upon one shaft and a piston carriedby the other shaft disposed in the cylinder, means for rotating theshafts simultaneously, means for mounting a drill on one of the shafts,means for introducing fluid 9 under pressure into said cylinder formoving one shaft with respect to the other, and means driven from one ofsaid shafts for intermittently interrupting the supply of uid underpressure to said cylinder and including a flow interrupter valve.

e. A drill press having a head and a Work table, a plurality of axiallyaligned shafts, means for moving said shafts longitudinally with respectto each other including a cylinder upon one shaft and a piston carriedby the other shaft disposed the cylinder, means for rotating the shaftssimultaneously, means for mounting a drill on one of the shafts, meansfor introducing hydraulic uid under pressure into said cylinder formoving one shaft with respect to the other, and means driven by one ofsaid shafts for intermittently interrupting the supply of fluid underpressure to said cylinder once each revolution and including a flowinterrupting valve and a flow metering device.

5. A drill press having a head and a work table, the combination of aplurality of axially aligned shafts journalled in the head, means forreciprocating said shafts with respect to each other including acylinder upon one shaft and a piston carried by the other shaft disposedin the cylinder, means for rotating the shafts simultaneously, means forconnecting a drill to one of the shafts, means for introducing fluidunder pressure in said cylinder for moving one shaft with respect to awork piece, and means driven by one of said shafts for intermittentlyinterrupting the supply of fluid under pressure to said cylinder afterthe said one shaft has approached to within a predetermined distance ofa work table.

6. A drill press having a head and a work table, the combination of aplurality of axially aligned shafts journalled in the head, means forreciprocating said shafts with respect to each other including acylinder upon one shaft and a piston carried by the other shaft disposedin the cylinder, means for rotating the shafts simultaneously, means forconnecting a drill to one of the shafts, means for introducing uid underpressure in said cylinder for moving said one shaft with respect to awork piece, and means l table, the combination of a plurality of axiallyaligned elements, means for reciprocating said elements with respect toeach other including a cylinder upon one element and a piston carried bythe other element disposed in the cylinder, means for rotating one ofthe elements, means for connecting a drill to said one of the elements,means for introducing fluid under pressure in said cylinder fortraversing said one element towards said Work table, and means driven instepped relationship with said one element for intermittentlyinterrupting the supply of fluid under pressure to said cylinder. l

8. In a drill press having a head and a Work table, the combination of aplurality of axially aligned elements, means for reciprocating saidelements with respect to each other including a cylinder upon oneelement and a piston carried by the other element disposed in thecylinder, means for rotating one of the elements, means for connecting adrill t0 said one of the elements, means for introducing fluid underpressure in said cylinder for traversing said one element towards saidwork table at a rapid forward traverse, and means driven in steppedrelationship With said one element for traversing said one element at afeed traverse following said rapid forward traverse including a deviceintermittently interrupting the supply of fluid under pressure to saidcylinder approximately once each revolution.

9. In a device ofthe class described for drilling a work piece, thecombination of a housing, a driven shaft, said driven shaft comprisingtwo members journalled in the housing and movable axially with respectto each other, a hydraulic element for moving said two members axiallywith respect to each other, means controlled by one of said members forcontrolling said element to remove it from its operation of moving saidmembers axially with respect to each other in stepped relationship withthe rotation of said members during rotation, and a drill carried by oneof said members for drilling the work piece.

JOHN W. KARWEIT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 92,419 Bates July 13, 18691,085,146 McClellan Jan. 27, 1914 1,911,132 Macomber May 23, 19331,978,879 Ferris et al Oct. 30, 1934 1,046,311 Lassiter let al. Dec. 3,1912 1,759,412 Noble May 20, 1930

